Abstract: The tool has a shank with a draw bolt threaded in an open recess in one end. A compression ring is mounted on the draw bolt and has an axially tapered outer peripheral surface. A burnishing ring is received about the draw bolt compression ring and axially engages the end of the tool shank. The burnishing ring has an outer diameter which is greater than the maximum outer diameter of the tool shank as well as being greater than the maximum outer diameter of the draw bolt. The burnishing ring has an inner diameter axially tapered surface which mates with the axially tapered outer peripheral surface of the compression ring. When the draw bolt is tightened it holds the compression ring tightly within the burnishing ring, thereby providing a mount for the burnishing ring. The burnishing ring has a precise desired outer diameter for burnishing a bore.

Abstract: A straight fluted gun drill having large flutes providing chip exit channels, various reliefs improving coolant flow and removal of drilled material without clogging, a cutting head section with large back taper, and straight lands forming the flutes.